1. Field of the Invention
The present invention relates to a vein imaging apparatus, a vein imaging method and a vein authentication apparatus.
2. Description of the Related Art
In the future networked society, a biometric individual authentication is a highly important technology to protect private rights. In particular, for commercial transaction in which money, contents and rights may be stolen across the Internet by spoofing of other persons, the biometric individual authentication has been paid attention as the technology for protecting an area which may not be solved only by a code. Here, an issue of forgery remains with a fingerprint and an iris. From this viewpoint, the individual authentication technology of a vein pattern utilizing a part which may not be easily imaged is expected to be the biometric individual authentication of the next generation because of accuracy of determination and difficulty for forgery and spoofing.
A fingerprint authentication technology and a vein authentication technology are examples of the biometric individual authentication technology. With the fingerprint authentication technology, there are issues that approximate four percents of users may not be registered and that resistance for spoofing by a remaining fingerprint may not be sufficient. However, there is an advantage that the sensor can be downsized since image composition can be easily performed with a scan type which utilizes a line sensor, an area sensor or the like. On the other hand, the vein authentication technology which is expected as the next generation authentication technology without having these issues is difficult to be mounted on mobile equipment etc. since the sensor is large. In particular, with an imaging type which utilizes a penetration image of vein, it has been difficult to configure devices to be plane-shaped since restrictions of location of a light source are severe.
In order to achieve downsizing of a device utilizing the vein authentication technology, a microlens array in which microlenses are arranged in an array shape is adopted in Japanese Patent Application Laid-Open No. 2008-36058.